Written November 2013 by M. Carena （Fermi National Accelerator Laboratory and the University of Chicago）, C. Grojean （ICREA at IFAE, Universitat Autbnoma de Barcelona）, M, Kado （Laboratoire de l＇Accelerateur Lin...Written November 2013 by M. Carena （Fermi National Accelerator Laboratory and the University of Chicago）, C. Grojean （ICREA at IFAE, Universitat Autbnoma de Barcelona）, M, Kado （Laboratoire de l＇Accelerateur Lineaire, LAL and CERN）, and V. Sharma （University of California San Diego）.展开更多
The minimal U(1)B_L extension of the Standard Model(B-L-SM)offers an explanation for neutrino mass generatio n via a seesaw mechanism;it also offers two new physics states,namely an extra Higgs bos on and a new Z'...The minimal U(1)B_L extension of the Standard Model(B-L-SM)offers an explanation for neutrino mass generatio n via a seesaw mechanism;it also offers two new physics states,namely an extra Higgs bos on and a new Z'gauge boson.The emerge nee of a second Higgs particle as well as a new Z'gauge boson,both lin ked to the breaking of a local U(1)B_L symmetry,makes the B-L-SM rather constrained by direct searches in Large Hadron Collider(LHC)experiments.We investigate the phenomenological status of the B-L-SM by confr on ting the new physics predictions with the LHC and electroweak precision data.Taking into account the current bounds from direct LHC searches,we demonstrate that the prediction for the muon(g-2)u anomaly in the B-L-SM yields at most a contribution of approximately 8.9×10^-12,which represents a tension of 3.28 standard deviations,with the current 1σuncertainty,by means of a Z'boson if its mass is in the range of 6.3 to 6.5 TeV,within the reach of future LHC runs.This means that the B-L-SM,with heavy yet allowed Z‘bos on mass range,in practice,does not resolve the tension between the observed anomaly in the muon(g-2)u and the theoretical prediction in the Standard Model.Such a heavy Z'boson also implies that the minimal value for the new Higgs mass is of the order of 400 GeV.展开更多
The cross sections of the Higgs production and the corresponding backgrounds of e^＋e^- annihilations at the CEPC（Circular Electron and Positron Collider） are calculated by a Monte-Carlo method, and the beamstrahlun...The cross sections of the Higgs production and the corresponding backgrounds of e^＋e^- annihilations at the CEPC（Circular Electron and Positron Collider） are calculated by a Monte-Carlo method, and the beamstrahlung effect at the CEPC is carefully investigated. The numerical results and the expected number of events for the CEPC are provided.展开更多
We present a SUSY model with four Higgs doublets of the"private type,"in which all fermion types(up,down,and charged leptons)obtain their masses from a different Higgs doublet H_f(f=u_1,d,e) .The conditions ...We present a SUSY model with four Higgs doublets of the"private type,"in which all fermion types(up,down,and charged leptons)obtain their masses from a different Higgs doublet H_f(f=u_1,d,e) .The conditions for anomaly cancellation imply that the remaining Higgs doublet of the model( H_(u_2) )must have the same hypercharge as H_(u_1) ,and thus,can only couple to up-type quarks,which opens the possibility to have FCNCs only in this sector.We study the Lagrangian of the model,and in particular,the Higgs potential,to identify the Higgs mass-eigenstates and their interactions;for the Yukawa matrices,we consider the four-texture case.We obtain constraints on the model parameters by using LHC measurements on the properties of the 125 GeV Higgs boson(h),and identify viable regions of the parameter space.Subsequently,these constraints are used to evaluate the prospects for detecting the FCNC decay mode t→ch at the future high-luminosity(HL)option for the LHC,which are compared with current limits from LHC-run2.Moreover,we evaluate the FCNC decay of the next heavier Higgs boson H_(2)→tc ,which can typically reach BR(H_2→tc)≈(10^(-4)-10^(-5)) .The search for the signal at HL-LHC is also studied,and it is found that it may be detectable for specific regions of the model parameter space.展开更多
We propose to measure the HZγ and Hγγ anomalous couplings in the process e^＋e^-→Hγ with the sequential decay of H→bb^ˉ. The discovery potential of observing the anomalous couplings are explored in detail.Our s...We propose to measure the HZγ and Hγγ anomalous couplings in the process e^＋e^-→Hγ with the sequential decay of H→bb^ˉ. The discovery potential of observing the anomalous couplings are explored in detail.Our study shows that future electron–positron colliders have great potential to test the HZγ and Hγγ couplings.Conservative bounds on the two anomalous couplings are also derived when no new physics signal is detected on top of the SM backgrounds.展开更多
基金supported by Fermilab,that is operated by Fermi Research Alliance,LLC under Contract No.DE-AC02-07CH11359 with the United States Department of EnergyC.G.is supported by the Spanish Ministry MICINN under contract FPA2010-17747+2 种基金the European Commission under the ERC Advanced Grant 22637 MassTeVthe contract PITN-GA-2009-237920 UNILHC.M.K. is supported by the ANR HiggsNet grant.V.S.is supported by the grant DE-SC0009919 of the United States Department of Energy
文摘Written November 2013 by M. Carena （Fermi National Accelerator Laboratory and the University of Chicago）, C. Grojean （ICREA at IFAE, Universitat Autbnoma de Barcelona）, M, Kado （Laboratoire de l＇Accelerateur Lineaire, LAL and CERN）, and V. Sharma （University of California San Diego）.
文摘The minimal U(1)B_L extension of the Standard Model(B-L-SM)offers an explanation for neutrino mass generatio n via a seesaw mechanism;it also offers two new physics states,namely an extra Higgs bos on and a new Z'gauge boson.The emerge nee of a second Higgs particle as well as a new Z'gauge boson,both lin ked to the breaking of a local U(1)B_L symmetry,makes the B-L-SM rather constrained by direct searches in Large Hadron Collider(LHC)experiments.We investigate the phenomenological status of the B-L-SM by confr on ting the new physics predictions with the LHC and electroweak precision data.Taking into account the current bounds from direct LHC searches,we demonstrate that the prediction for the muon(g-2)u anomaly in the B-L-SM yields at most a contribution of approximately 8.9×10^-12,which represents a tension of 3.28 standard deviations,with the current 1σuncertainty,by means of a Z'boson if its mass is in the range of 6.3 to 6.5 TeV,within the reach of future LHC runs.This means that the B-L-SM,with heavy yet allowed Z‘bos on mass range,in practice,does not resolve the tension between the observed anomaly in the muon(g-2)u and the theoretical prediction in the Standard Model.Such a heavy Z'boson also implies that the minimal value for the new Higgs mass is of the order of 400 GeV.
基金Supported by CAS/SAFEA International Partnership Program for Creative Research Teamsfunding from CAS and IHEP for the Thousand Talent and Hundred Talent programsgrants from the State Key Laboratory of Nuclear Electronics and Particle Detectors
文摘The cross sections of the Higgs production and the corresponding backgrounds of e^＋e^- annihilations at the CEPC（Circular Electron and Positron Collider） are calculated by a Monte-Carlo method, and the beamstrahlung effect at the CEPC is carefully investigated. The numerical results and the expected number of events for the CEPC are provided.
文摘We present a SUSY model with four Higgs doublets of the"private type,"in which all fermion types(up,down,and charged leptons)obtain their masses from a different Higgs doublet H_f(f=u_1,d,e) .The conditions for anomaly cancellation imply that the remaining Higgs doublet of the model( H_(u_2) )must have the same hypercharge as H_(u_1) ,and thus,can only couple to up-type quarks,which opens the possibility to have FCNCs only in this sector.We study the Lagrangian of the model,and in particular,the Higgs potential,to identify the Higgs mass-eigenstates and their interactions;for the Yukawa matrices,we consider the four-texture case.We obtain constraints on the model parameters by using LHC measurements on the properties of the 125 GeV Higgs boson(h),and identify viable regions of the parameter space.Subsequently,these constraints are used to evaluate the prospects for detecting the FCNC decay mode t→ch at the future high-luminosity(HL)option for the LHC,which are compared with current limits from LHC-run2.Moreover,we evaluate the FCNC decay of the next heavier Higgs boson H_(2)→tc ,which can typically reach BR(H_2→tc)≈(10^(-4)-10^(-5)) .The search for the signal at HL-LHC is also studied,and it is found that it may be detectable for specific regions of the model parameter space.
基金Supported by National Science Foundation of China(11275009)
文摘We propose to measure the HZγ and Hγγ anomalous couplings in the process e^＋e^-→Hγ with the sequential decay of H→bb^ˉ. The discovery potential of observing the anomalous couplings are explored in detail.Our study shows that future electron–positron colliders have great potential to test the HZγ and Hγγ couplings.Conservative bounds on the two anomalous couplings are also derived when no new physics signal is detected on top of the SM backgrounds.
